I.IFE-HISTORIES. 225 



fJlOTES ON LIFE-HISTORIES, LARV^, &c. 



Ovum of Lachneis i.anestris. — The account of this egg in Tutt's 

 British Lepidnptera, vol. ii., p. 507, is not at all points quite as com- 

 plete as it should be. The point chiefly in need of being more 

 definitely brought out is the flattening of the egg. In the whorls in 

 which it is placed, the micropylar end is outwards, and, as stated, 

 this end of the egg is rather larger than the other ; but further, as it 

 is usually placed on the twig, the thickness of the egg parallel with 

 the length of the twig is greater than that transverse to it, i.e., re- 

 garded as a flat Qgg, it has the long micropylar axis, but the other two 

 axes at right angles to this are unequal, a fact that is not mentioned 

 in the description referred to='S and yet most important as showing that 

 this egg has made no serious progress from the flat to the upright 

 type of egg, notwithstanding that its position when laid more suggests 

 an upright than a flat position. The details said to be seen under 

 a f lens are for the most part invisible under a half-inch object-glass, 

 nor do I make out a circular depression on the " upper surface " of the 

 egg. (Which is the upper surface?) The long axis of the egg, 7.^., 

 from micropyle to nadir, is 1-Bmm. Viewed from above, looking 

 straight down on micropyle, the diameters at right angles to each 

 other are the longer OvSGmm., the shorter 0-58mm. ; we may, therefore, 

 describe it, as in other flat eggs, as having a top, a side, and ends, 

 though here, as the egg is laid, the " end " (micropylar) is at the 

 top. Or we might, in view of such eggs as this — and to make terms 

 of description the same in flat and upright eggs — describe the egg as 

 having a top or summit (micropylar end) and a nadir, and a side and 

 an edge — the side being that aspect which gives the Qgg its largest 

 apparent area. The form of the egg is then further to be described as 

 giving the side a diameter at the top (micropylar end) of 0-74mm., at 

 the middle of 0-84mm., and at the base of 0-6Sinm. The same 

 diameters on the edge view being 0'74mm., 0-68nnu., and O'oOmm. 

 One of the sides is generally somewhat irregularly hollow i . As to the 

 colour of the egg, the woolly coating is not difficult to remove 

 sufficiently for the egg to be seen, but it remains more or less covered 

 with gummy matter. Allowance for this suggests that the colour is 

 really a slightly dirty white. The depression in the side, as in most 

 flat eggs, is probably the result of shrinking by evaporation. No 

 other depression can be made out. The micropylar area is slightly 

 thinner than the rest of the eggshell, and shows a trace of difterent 

 tint not always easy to be sure of. As to markings and sculpture, the 

 micropyle presents a rosette of eight cells, with a diameter of 0-04mm., 

 which is thinner than the rest of the eggshell. The rosette is 

 surrounded with hexagonal cells somewhat elongated in a radial 

 direction, and getting lai'ger outwards till they are about twice the 



* The typical Lachneicl egg is described {Brit. Lep., ii., p. 43o) as having " the 

 micropylar axis horizontal, and usually considerably longer than either of the 

 other axes, of which the vertical is the shorter." As the typical characters relating 

 to these three axes are maintained in /,. hniestri.<. they have not been repeated 

 on p. 507.— Ed. 



t Probably this represents the badly-termed " upper surface," the depression in 

 the particular egg described {liril. Lep., ii., p. .507) being almost vegnlar instead of 

 irregular. — Ei>. 



